Draft stabilizer



Jan. 18, 1938. E. A. FIELD ET AL 2,105,724

DRAFT STABILIZER Filed July 26, 1935 WW SM ATTORNEYS Patented Jan. 18, 1938 UNITED STATES PATENT OFFICE DRAFT STABILIZER Application July 26, 1935, Serial No. 33,243

2 Claims.

The main objects of this invention are:

First-To provide a draft stabilizer which is well adapted for mounting on the smoke flues of furnaces, being adaptable to flues in various positions and at various pitches.

Second.--To provide a draft stabilizer of this character which is highly effective throughout a wide range of conditions and one in which the deposit of soot and ash within the stabilizer is effectively prevented.

Third.-To provide a structure having these advantages which is very simple and economical in its parts and may be easily mounted and adjusted by workmen not particularly skilled in the mounting thereof.

Objects pertaining to details and economies of our invention will definitely appear from the description to follow. The invention is defined in the claims.

A structure embodying the features of our invention is clearly illustrated in the accompanying drawing, in which:

Fig. 1 is a fragmentary plan view of an embodiment of the invention, the chimney or stack being conventionally illustrated in horizontal section.

Fig. 2 is an enlarged fragmentary elevation.

Fig. 3 is a fragmentary view mainly in vertical section on line 3-3 of Fig. 2.

Fig. 4 is a detail section on line 44 of Fig. 3.

Fig. 5 is a detail section on line 5-5 of Fig. 3.

In the accompanying drawing, 1 represents a heating furnace, 2 the chimney or stack and 3 the smoke flue. We provide a stabilizer housing 4 having an inlet opening 5 in its front wall and an outlet opening 6 in its rear wall, the outlet opening being surrounded by a cylindrical rearwardly projecting flange I. This flange is partially formed with the wall of the housing and partially of the segmental flange member 8, see Figs. 3 and 5.

We have not illustrated the joints of the housing but in practice they are made up of sheet metal parts, suitably joined together as may be 45 found most economical and convenient in manufacture.

The front opening is provided with a draft gate 9 having forwardly and downwardly projecting pivot member ID resting upon the pivot ledge 5 II. An arm l2 projects downwardly from this pivot member and is provided with a toothed segment I 3 with which the weight I4 may be selectively engaged. A thumb screw 15 is provided for securing the weight in adjusted posi- 55 tion. The counterbalance is preferably arranged to function as shown in Patent 1,783,418, December 2, 1930, issued to Edward A. Field and Edward A. Field, Jr.

To function more emciently the housing should be mounted so that the pivot of the gate is in 5 a horizontal plane. The mounting comprises a cylindrical collar l6 rotatably mounted on the flange l or rotatably associated therewith. This collar has curved recesses I! in its inner end adapted to fit against the side of the smoke 10 flue and embracing the opening 18 formed therein. The front end of the collar abuts against the lug l9 at the top of the housing and against the rear wall of the housing at the under side of the flange 8 and is clamped in its adjusted position by 15 means of the strap 2| secured at one end to the lug l9 by means of the bolt 22 and at its other end to the housing by means of the bolt 23.

The housing is provided with a discharge flue 24 which projects into the opening I8. This is preferably rearwardly tapered as illustrated, being made up of complementary sections 25 and 26 pivoted together at their inner ends at 21 and secured at their front ends to the housing by means of bolts 28 and the angled clips 29.

Our discharge flue projects a little way into the smoke pipe and this causes a different action than would be the case if it were set back farther into the housing of the draft stabilizer. If a tube is inserted at right angles into a passage in which there is a flow of gas, a vacuum will be produced in this tube in spite of the fact that there may be a slight pressure in the duct. Our discharge flue has somewhat the same effect. The end of the flue is smaller than the smoke pipe and the smoke is deflected around the top and bottom. The air from the control is directed into the center of the smoke passage and is more effective in checking the draft than it would be if permitted to enter along a line more or less tangent to the outside of the smoke pipe; i. e., less air is required to accomplish the results than would be the case if it were not directed toward the center of the smoke pipe. If there is no discharge flue, the smoke tends to eddy at the corner where the collar of the draft stabilizer attaches to the smoke pipe. However, when the discharge flue is used, the smoke simply deflects around the same.

With this arrangement of parts the stabilizer can be quickly mounted on smoke flues in various positions and on flues having widely varying pitches with the housing in upright position or in position to bring its gate pivot into horizontal position.

embody or adapt the invention as may be desired.

Having thus described our invention what we claim as new and desire to secure by Letters Patent is:

1. In a draft stabilizer, the combination with a smoke flue having a side opening thereof, of

a housing having an inlet opening in its front wall and an outlet opening in its rear wall provided with a cylindrical rearwardly projecting flange, a cylindrical collar'recessed on its inner end to fit the sideof the smoke flue at the outside of the opening thereof, the housing flange being rotatably adjustable on said collar to permit the vertical positioning-of the housing, a clamping means for securing-the housing'and collar to said smoke flue with the housing in its adjusted position, a discharge flue'for said housing projecting into-said opening in said smoke flue, said discharge flue comprising a pair of segmental complementary sections pivotally connected at their inner ends, their outer ends being connected to said housing, a gate for said inlet opening pivotally mounted at its lower end to swing inwardly in opening, an arm carried by said gate and projecting below its pivot, and a counterbalance for said arm.

2. In a draft stabilizer, the'combination with a smoke flue having a side opening therein, 01 a housing having an inlet opening and with an outlet opening provided with a cylindrical rearwardly projecting flange, a cylindrical collar conformed to fit against the side of the smoke flue at the outside of the opening thereof, the housing flange being rotatably adjustable on said collar EDWARD A. FIELD. EDWARD 'A. FIELD, JR. 

